- Technical info can be found on this Ranfft page
- This movement with micro-rotor was produced in the 1980s
This movement with micro-rotor was produced in the 1980s for thin watches as a response to quartz movements. As the micro-rotor goes above the fourth wheel (placed at the centre of the movement), it is proportionally large at 14mm for a 26mm movement (54%). The movement has directly driven seconds, but indirectly driven minutes.
The pinion sticking out of one of the wheels of the automatic system drives a gear on the underside of the barrel bridge. The latter then winds the barrel.
The second wheel, in addition to driving the third wheel, drives an intermediate wheel on the dial side that then drives the cannon pinion. This is how the minutes are indirectly driven, whereas the fourth wheel is at the centre and directly drives the seconds hand.
On the dial side, there is a wheel at 8 o’clock that drives the date change and is itself driven by the hour wheel (missing here). At the centre, the intermediate wheel indirectly driving the cannon pinion is visible. It is attached in a way that it will slip when the canon pinion is moved by the keyless system for time correction. It connects to the second wheel through the dial at about 1 o’clock.